Effect of drought stress and different planting dates on safflower yield and its components in Tabriz region

In order to study the impact of drought stress and planting date on safflower yield and yield components, an experiment was performed in tabriz region in 2011. the experiment was carried out as split-split plot based on randomized complete block design. the main factor which was applied as split plot includes drought stress with three levels: (s1) 80 ± 3 mm evaporation from basin level of class a, (s2) 120 ± 3 mm evaporation from basin level of class a, (s3) 160 ± 3 mm evaporation from basin level of class a. the subsidiary factor studied in this research was studying 2 levels of planting date including (d1): conventional planting date in region (date: 2011/4/19) and (d2): 20days later from conventional planting date in region (date: 2011/5/9). the sub-subsidiary factor was two different safflower cultivars include (v1): isfahan local cultivar and (v2): goldasht as modified cultivar. according to results the impact of drought stress on plant dry weight and leaf dry weight, plant height, number of branches and sub-shrubs, capitul in plant and seed in capitul as well as seed yield was significant. the effect of planting date on the traits being studied in this research was significant. the interaction of drought stress and planting date, except in dry weight of leaf, was not significant in other traits